1. Technical Field
The present invention generally relates to storage subsystems and their internal communications as well as their communication with host computer system and, more particularly, with how high-function storage subsystems can be created without any internal communication unique to their subsystem. More specifically, relates to a technique for providing all of the functions of a closed storage subsystems without requiring either the storage media or the processing units involved to be hardware unique to a single vendor.
2. Description of Related Art
Storage subsystems today are structured so that they physically include both processing power and storage media, which includes such elements as disks, tapes, etc. It is on these storage media the storage subsystems operate.
Processing power is provided by one or more commonly used computers. The storage media is attached to the input/output (I/O) system of a computer, or a plurality of computers, also referred to as client systems. Specifically, the storage media is attached to an adapter that allows communication with a client systems by a communication mechanism such as fiber channel (FC), Serial Storage Architecture (SSA), etc. The storage media are typically connected using a facility, such as the small computer system interface (SCSI), SSA, or the like.
The processing power provides various functions, such as backup, and reflection to remote storage for disaster recovery, and the like. A main memory of the storage subsystem is used to cache data from the storage media.
The processing unit provides functions that are desirous for users or customers. Further, it is also desirable to encapsulate the storage media inside the storage unit because this prohibits undesired (non storage subsystem) access to the data stored on the storage media.
However, known systems that have the storage media embedded in the storage unit, sometimes referred to as closed storage subsystems, are undesirable. The embedded system locks or limits a user into the storage elements sold or produced by a particular vendor or a manufacturer of the storage subsystem. Since unique packaging and other characteristics can be defined or applied by the storage system vendor or manufacturer, they are vendor specific. Thus, the vendor specific storage subsystem makes it more difficult for end user modification of the subsystem. This also makes it more difficult to upgrade to new, better storage products, since they must be adapted to the storage subsystem. For example, if more storage is needed in the closed system, the only option is to buy from the original vendor or vendor specific products because of compatibility issues.
Therefore, it would be desirous to have a storage subsystem wherein the storage media or elements are not vendor specific.
An open format storage subsystem and method are provided. The storage subsystem and method include at least one host endnode, at least one processing unit endnode, and at least one storage endnode. These endnodes are partitioned according to partition tables assigned to the ports of the endnodes and partition keys assigned to queue pairs of the ports.
Based on these partition keys, partitions are defined that restrict access to the storage endnode or endnodes, allowing only the processing unit endnode to control them; and others defined that allow the host or hosts to access the processing endnode or endnodes. This has the effect of encapsulating the storage endnodes within a logical storage subsystem, while allowing access to said storage subsystems""s functions by the hosts through the processing unit endnodes. In this way all of the functions provided by prior storage subsystems are provided, but the elements of the storage subsystem, e.g., the processing endnode or endnodes and the storage endnode or endnodes, can be sold or purchased as separate individual units, participating in commodity economies of scale.
These and other features and advantages of the present invention will be described in, or will become apparent to those of ordinary skill in the art in view of, the following detailed description of the preferred embodiments.